Maternal effects and heterosis in tomato across twelve phytochemical and quality traits

Reciprocal crosses and F1 hybrids revealed maternal effects and heterosis, highlighting the role of genetic background and parent selection in enhancing tomato quality. This study assessed ten tomato genotypes, including parental lines, F1 hybrids, and reciprocal crosses, to evaluate maternal effects, heterosis, and genetic variability across twelve phytochemical and quality traits using a completely randomized design with three replications. Significant maternal effects were observed for total soluble solids (TSS) and lycopene. For instance, GN × Siltez showed higher TSS (7.20%) than Siltez × GN (6.33%), while Medford × GN produced more lycopene (34.57 mg/kg) than GN × Medford (16.34 mg/kg). Heterosis analysis revealed both positive and negative effects; specifically, Siltez × GN showed high mid-parent heterosis (MPH) for flavor index (86.54%) and lycopene (57.30%), whereas GN × Medford exhibited extreme MPH for total carotenoids (2125.35%). High genotypic variation occurred in titratable acidity (19.62%), lycopene (34.18%), and anthocyanins (162.64%). Traits with high heritability (H2 ≥ 0.71), such as titratable acidity, anthocyanins, and phenolic content, offer potential for selection, while moisture and pH were environmentally influenced. Principal component analysis highlighted Siltez × GN and GN × Siltez as promising for flavor and ascorbic acid, supporting their use in quality-focused breeding.